Screw propeller



FIG. 1 is a perspective view of the screw propeller;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a right side view, the left side being a mirror image thereof;and,

FIG. 5 is a top view thereof, the bottom side being a mirror imagethereof.

CLAIM The ornamental design for a screw propeller, as shown anddescribed.